Okay so my ex is being weird. PLS HELP

Okay so my ex boyfriend ha da girlfriend but I’ve been low lately due to the whole breakup (I’m still upset over it and yes he moved on within a month or something) and he came to get his stuff but I got upset after the left and he rang me which is when he found out I was upset, he offered to come to my house another day to talk and to comfort me, I feel like this is him cheating on his girlfriend and I feel bad but could rlly do with comforting from the one person I’m use to getting comfort from, I’m over the relationship... I miss it but I don’t want it back so this won’t upset me too much in the long run.

What does this mean and what should I do or say to him? PLEASE HELP