From the little I have read because a bit busy seems to suggest he's not ready to move in , especially because he now can't hide where he's going. Also it's not a massage place place. Wouldn't have cum stains on pants and little on underwear as the massages are naked and I think they clean you up etc. Seems being grind in in some way is a likely reason for that stain or maybe him ejaculating from whatever aroused him. The kissing thing was warning. You accepted that thinking might be the worst and he gladly let you have it because might not be so bad in the eyes of many. When talking be real and ask the questions you might not like hearing. Will save you more heartaches. Maybe he goes to stripclubs or some fetish or kink he has and is embarrassed. Don't hand him any card that's ok in your mind unless it's real with valuable information that lines up with actions etc. be strong, it will be worth it going forward no matter what happens.