The above question has been emailed to me on several occasions. If we sin, we grieve the Holy Spirit. If we repent, we restore our relationship with Him. Psalm 51 shows the steps to take. It is below from The Passion Translation.

A prayer of confession when the prophet Nathan exposed King David’s adultery with Bathsheba

God, give me mercy from your fountain of forgiveness! I know your abundant love is enough to wash away my guilt. Because your compassion is so great, take away this shameful guilt of sin. Forgive the full extent of my rebellious ways, and erase this deep stain on my conscience. (3-4) For I’m so ashamed. I feel such pain and anguish within me. I can’t get away from the sting of my sin against you, Lord! Everything I did, I did right in front of you, for you saw it all. Against you, and you above all, have I sinned. Everything you say to me is infallibly true and your judgment conquers me. Lord, I have been a sinner from birth, from the moment my mother conceived me. I know that you delight to set your truth deep in my spirit. So come into the hidden places of my heart and teach me wisdom. Purify my conscience! Make this leper clean again! Wash me in your love until I am pure in heart. Satisfy me in your sweetness, and my song of joy will return. The places within me you have crushed will rejoice in your healing touch. Hide my sins from your face; erase all my guilt by your saving grace. Create a new, clean heart within me. Fill me with pure thoughts and holy desires, ready to please you. May you never reject me! May you never take from me your sacred Spirit! Let my passion for life be restored, tasting joy in every breakthrough you bring to me. Hold me close to you with a willing spirit that obeys whatever you say. Then I can show to other guilty ones how loving and merciful you are. They will find their way back home to you, knowing that you will forgive them. O God, my saving God, deliver me fully from every sin, even the sin that brought bloodguilt. Then my heart will once again be thrilled to sing the passionate songs of joy and deliverance! Lord God, unlock my heart, unlock my lips, and I will overcome with my joyous praise! For the source of your pleasure is not in my performance or the sacrifices I might offer to you. The fountain of your pleasure is found in the sacrifice of my shattered heart before you. You will not despise my tenderness as I humbly bow down at your feet. Because you favor Zion, do what is good for her. Be the protecting wall around Jerusalem. And when we are fully restored, you will rejoice and take delight in every offering of our lives as we bring our sacrifices of righteousness before you in love! (Ps. 51:1-19 TPT)

Then I received this follow-up question

"Do you think HIV would be the only thing the Holy Spirit could not dwell with?"

My answer is below

Jesus describes and exhibits what a godly Spirit-anointed lifestyle looks like

  • He who has My commandments and keeps them is the one who loves Me ... and I will love him and will disclose Myself to him (Jn. 14:21; Lk. 24:32).
  • Conclusion: LOVING and OBEYING Jesus results in RECEIVING REVELATION from Him. (Jn. 14:3,24; 15:4-10)

The Holy Spirit empowers us to experience the Christian lifestyle 

  • Jesus ALWAYS had the Spirit's anointing because He always obeyed God (Jn. 8:29). Although He was a Son, He learned obedience through the things which He suffered (Heb. 5:8).
  • I will ask the Father, and He will give you another Helper, that He may be with you forever; that is the Spirit of truth ... you know Him because He abides with you and will be in you (Jn. 14:16,17). 
  • But the Helper, the Holy Spirit ... will teach you all things, and bring to your remembrance all that I said to you (Jn. 14:26). These truths are repeated in John 16:13-15; 17:3.

Summarizing the lifestyle of living tuned to the Spirit

We love Jesus and keep His commands (Jn. 14:21; Lk. 24:32). We keep the eyes of our heart fixed upon Jesus, Emmanuel, the One who is always with us (Heb. 12:2; Acts 2:25; Ps. 16:8). The Holy Spirit within discloses revelation to us. We hear God's voice, see God's visions, are empowered by the Holy Spirit to live righteously, and the result is we experience God's kingdom emotions of joy and peace (Rom. 14:17; Jn. 7:37-39; Jn. 14:27). Jesus demonstrated how one walks and lives by the Spirit, which is why we imitate Christ (1 Cor. 11:1). "He who sent Me is with Me; He has not left Me alone, for I always do the things that are pleasing to Him" (Jn. 8:29).

So these verses are crystal clear. All sin grieves the Holy Spirit. Just like every time I say a harsh word to my wife or a friend, I grieve that relationship. This is why we are told to only speak words edifying for the need of the moment so it may give grace to those who hear (Eph. 4:29).

So we are to live as Jesus lived, always doing the things that are pleasing to God. Whenever we sin, we have put up a barrier between us and God, so then we do what King David did. We repent of our sin and ask for God's cleansing and forgiveness. That is our lifestyle.

I am not comfortable picking out any certain sin and saying it is worse than any other sin.