My take on what you said (assuming your UPDATE reassuring us it is real lol)
Ashley reaction to me indicates that she told him about the prank because she felt guilty about it, because any decent woman after a guy said all those nice words, would have stepped in and said "Yes thank guys for setting us up" then a few weeks later would have said don't think it is working and you should split up.
So assuming she did tell him about the prank, Jim played an Oscar winning performance and is now punking your ass lol.
Version 2 (probably the reality):
You fucked with his emotions and Ashley was gutless and wanted you to admit to the prank. Now he will hate you forever, may turn to drugs, turn to eating and gain a lot of weight. Then eventually worst case may commit suicide. Then on his Gravestone it will say "Thanks DIngDong and Tim for cutting my live short"
Instead of actually committing suicide he would pretend to do it and punk your asses at the funeral.
Version 3.0 (pray this never happens):
He has no trust in women and love any more and turns into a serial killer.