You deal with it by doing absolutely nothing. When you react, you play right into their hands which is exactly what they want. In order for the situation to not escalate, somebody has to be the bigger person, so let that person continue to be yourself. If you trust your boyfriend & if he has given you no cause to doubt him, then there is no problem. Your relationship with your boyfriend is between you & him. The only way these other people can have a say or place in the relationship is if either you or him allow them that. As long as that is not happening, then these people are nothing. They don't exist. As far as them crossing the line with your boyfriend, again, that's between you & HIM, not these other people. Your boyfriend should be setting boundaries & demanding that others respect them. If he permits others to cross those boundaries, then perhaps he is not as invested in the relationship as you are. If that's the case, then you must decide if that's something you can tolerate.