Advice??

So I lost my v-card last night to a boy I like but wont commit to a relationship by calling me his gf. (I honestly think I only had sex with him because I'm afraid he will leave and that's the only way he will stay) this man is perfect,treats me right and everything with the exception of commitment.And my mom always says how I cant lie to her (meaning I'm to tell her when I loose it) but I scared to tell her because shes controlling. So basically what I'm asking is should i tell her and let her be mad when she finds out ( my sister will most likely tell her without me knowing) or keep it to myself because i dont have the type of relationship with my mom to where i want to tell her about my love life let alone sex life (keep in mind I'm 19).