Boyfriend?¿

Ok so me and my ex boyfriend broke up in the beginning of June after being together for almost a year (June 23rd would’ve been a year) because of cheating issues with him and stuff and we thought he was going into the Military so he didn’t want to hurt me when he went anyways just a couple months ago we started seeing each other again and like hanging out after work and basically acting like a couple again well his mom didn’t want him talking to me because she didn’t want him to hurt me again well now since we’ve been secretly talking we wanna talk to his mom about getting back together (she loves me) (he’s 18 I’m almost 18) so should we talk to her in person or on a group text because either way we’re screwed because she’s gonna know we’re talking but we wanna show he really wants to be with me and he’s not a kid anymore so how should we go about this?