So I'm single (and preggo---he left me for someone else)

Anywho, he left his book bag and some of his things in my house tho so I'm wondering should I message his sister/gf and say "ah your man(for the gf)/bro (for the sis) left his bookbag is someone coming to get it or nah?" Or should I just toss it in the garbage. Is it being too petty if I message them and let them know? I'm sure the gf doesn't even know he got anutha baby on the way & he over there playing stepdaddy to her 4 kids

Ladies what would you do in this situation? His gf status says they was together since Jan 1st but I'm sure it was before that considering he called me the day before and said he was in the hospital & just got out, barked on me for "caring too much" & hung up

FYI I haven't kept him out of this 👶🏾 picture (due in August) he hasn't asked about the baby since I told him and YES it's his (in case the judgemental comments start rolling in) just wondering what you ladies would do about a situation like this....message the gf/sis (both or 1 of them) or just toss out the bookbag?