On & off friendship but I really like him

A year ago I started talking to a guy I met through fb (I’ll call him David) David reached out to me first and I responded, during that time I was having issues with my ex so I found comfort in David.. it was an on & off communication we went almost 5 months without talking and then again he reached out to me and we talked all day, everyday for almost 2 weeks till he finally asked to hang out we both love to dance so we went to the club. The day after we hung out I immediately received a msg from the mother of his child. She went off on me and I couldn’t stay quiet so I responded back the same way she came to me. She kept saying that she was with him that they were together the night before and that I was messed up for ruining a family. But he on the other hand says he’s single and that shes crazy so I just blocked her. David and I continued to talk. During that time my ex was begging for me back so I made the dumb decision to take him back and I had to cut off ties with David... the relationship never last and again I reached out to David. We hung out again at the club but this time I swear I felt different the vibe was different, I’m falling for David I really like him but the mother of his kid messaged me again he confessed that they were in a relationship but broke up with her for me, because he felt nothing for her and I made him happy. We talk on & off again but I’m not sure if I should continue this? I really really really like him but up to this point idk if he’s the liar or if she is.. I’m 25 & he’s 21 not a big difference but he claims to be mature...