Is it okay to have multiple sex partners?

My ex (first love) and I broke up a year and a half ago and continued hooking up ever since which I admit at times got hard with feelings but we stay at a distance. However recently I started seeing this other guy (whose amazing) and he kinda seems like he’s just looking for a sex buddy which I’m 100% okay with. I feel some guilt about hooking up with someone new and still hooking up with my ex. Should I tell them? Should I only stick to one sex partner? Both guys are amazing in bed and amazing guys in general