Most Helpful Guy
My ex-girlfriend only wanted to use me for sex. That will never happen again.
Most Helpful Girl
Honestly I would just try to not think about/worry over something that's in the past, but if you do feel like you've missed out on a perfectly good relationship and that you could have done something differently, then just take that as a learning lesson for the next relationship.
When getting into a relationship, make sure to treasure your significant other and treat them as precious beings you whom you want to stay in your life. If you want them to stay, you have to put the effort in- always be sure to show them exactly how much they mean to you :)