can you tell an ex not to contact your current bf?

AND vise versa: can you tell your current bf not to contact your ex when your ex reaches out (of course, to protect your partner)?

what is the smartest course of action:

my ex was emotionally abusive towards me and I still have some low key form of PTSD from all the stuff he did to me. he did lots of yelling and manipulation to get sex. he keeps on asking my current boyfriend to hang out and "jam" because they both are musicians. but it's a coverup to get close to my boyfriend or try to hurt him too because my boyfriend and I are both very sweet people. I wouldn't mind it if I knew my ex wasn't emotionally abusive and if we ended on good terms.