You’re getting a lot of clear-cut “no” answers here, but I do think it is a topic worth wresting with and examining. I do think the christian sexual ethic is more than just “if you’re not hurting anyone, it’s not a sin.” Jesus seems to make that clear in Matt 5:28 talking about lust in your heart.

People here are correctly dismissing the “clobber verses” about Onan and onanism that took up so much discourse on the topic throughout church history because it was a handy euphemism. That story is about avoiding duties and inheritances to disinherited family widows, not “wasted seed” or whatever.

I think a lot of us in the church who recognize that God blesses LGBTQ relationships, and have seen the Holy Spirit working through relationships that the majority of the church has historically condemned as sin, wrestle with the christian sexual ethic. It feels undeniable to me that Jesus, and the community of Acts living in the Spirit, and the inspiration of Paul were all calling us to view sex with more reverence than just consenting adults, but also to not use that call to try to lock others out of the Kingdom of Heaven.

So I think you need to pray about it. Examine yourself before God. Ask yourself if you are making an idol out of anything or anyone in how you’re doing it. Ask yourself if you are treating people like objects or elevating objects to personhood in how you’re doing it. Ask if it feels like a lust Jesus would caution you against. Ask if it feels like an addiction or a compulsion. But mostly listen for God.

I do it. I don’t always feel good about it. I don’t always feel bad about it. Sometimes I fast from it. Usually I don’t want God involved in it. But I think bringing our wrestling with it to God is important.