Just try to get in an actual relationship before you have sex with him, it makes sex like 100% better knowing its someone you love and someone you're in a relationship with, its not as special with just a guy you've sent pics to and stuff.
If you know him on a personal level and you want to be in a relationship obviously, you've taken a liking to his personality and its not just the pics you've take a liking too.
Ehh every guy is different.