Look at her track record, Dan is perfect man she would fall in love with.
We have Jack who raped Kayla and was the bad boy everyone warned her against.
We have, oh god I forget his name the dancer, that was the bad boy everyone warned her against, isn’t he who she was going to marry when Jack took her away in the fire truck
We have Peter and I can’t even remember all the bad stuff he did
Then I swear there was a guy the last time she returned that wasn’t very good either.
The only guy that was ever "good" was Frankie. Every other guy she has fallen for has always been the bad boy, it is right in character with Jennifer to fall for him. Plus the guy is HOT which for anyone that went through a divorce and just dealt with what she did with Jack would fall for. Makes her feel good about herself after the way she just got ignored by her own husband.