mark my territory!

so lastnight i was talkin to the guy friend that i like and we were talkin and talkin about our "experiences" we have with each other and he was like i have been wantin to mark my territory for a long time and i asked him what did he mean by that and he says nothing im just being mannish....i kind of had an idea of what he meant but i wasnt sure and im still not sure so what does a dude mean by marking their territory???