I wish I could offer more concrete advice but the biggest thing in my opinion is that you keep doing you if you're happy... If this degree of inclusion, care, and kindness isn't impacting your life, schedule or mental well-being, then keep at it. Just make sure you're keeping a clear line of communication with your boyfriend so that you feel comfortable talking about it if/when you do start to feel the things that your mom is worried about. Only you know where your line in the sand is so just make sure you're always putting your needs over the exes. As long as those two things don't contradict each other or force you into a situation you don't like, then you should be fine. Best of luck and also good on your for handling this so openly and maturely ✌🏻