That depends on the guy. Some are jealous, some are not.
Jealous
Use reverse psychology. Get another boyfriend to make your ex jealous. And if you can't get another guy, ignore it. Act COMPLETELY oblivious to his new relationship.
You answered it yourself. He got with the other girl to make you jealous. It doesn't make a whole lot of sense.
Guys may make fun of other guy's legs because they are jealous.
To date another guy to make the one your dating mad
If you still like that person then make her or him jealous by going out with there friend or something that will make them jealous. But if your just jealous and you dont like that person than just forget about it. this as been answered by Austin Bissonnette
find out if he likes you first if he says yes then make him a little jealous by talking bout another guy if he says no then it couldn't hurt to try a bit of flirting and make him a bit jealous. hope it helped
He either is trying to make you jealous or he doesn't want you to be jealous
A girl who is trying to make you jealous will only flirt with another guy in front of you. Anything more than just flirting means she's not doing it just to make you jealous.
Most likely
make him jealous of you