I don't know what they can get out of looking at someone's profile for so long.
They can see all my posts via my profile. And my stats too of course.
Just think of them clicking on your profile to get on your nerves. Every time they want to make dinner or have a cup of coffee, they make an effort not to forget to click on your profile. Even when they go to the bathroom, they may make the effort of clicking on your profile.
Don't think anything more about that. Don't fret. Don't let it spoil your fun here. The best "ignore" is done in your head. It is the obsession of the people looking. Don't let it become your obsession too.