Boyfriends ex-girlfriend texting him?

So the other day my boyfriend told me that his ex-girlfriend texted him & was talking about wanting to get back together with him. He said she was even talking about getting married, like wtf. He even told me that this isn't the first time an ex has tried to get back with him. He told me that he ignored her & didn't reply to her texts. I trust him & don't think that he did but I don't like the fact that he has ex-girlfriends randomly texting him & wanting to get back together. Mainly because I don't know what else they're saying or if they're sending him pics of themselves. The whole thing just makes me kind of insecure. Should I just leave it be & trust that he's just ignoring her or should I make sure that he either asks her to stop texting him or blocks her?