Territorial cuddles?

[Loveineveryspoonful]

Dh and I have 3 dc between us with varying "degrees of contact".
Ds, 15, ft/ dss, 12, 50:50/ dsd, 16, eow and 1 midweek sleepover.
Over the last 4 yrs I couldn't help but notice certain behaviour during family viewing nights which I'd sooner class as openly territorial and therefore passive/aggressive. They are all prone to it at different times and I'm just wondering how to tackle it, if at all.
What usually happens is that, e.g. Dsd would be watching tv, dh and I might join her or want to watch a film etc and she'd put her legs over dh in a rather aggressive way, leaving no other interpretation open except to say "he's mine". My hackles rise...
Or dh and I might be watching a DVD and dss joins us and immediately places his feet into dh lap for a foot rub (never politely requested, btw), something dh did for them when they were quite young, does not really want to do anymore. Dss quite insistent though, sometimes nudging dh quite harshly with said feet. This I can happily ignore. What gets my goat is when dh pulls me closer or turns to me ever so slightly (usually a kissing scene...) and dss immediately launches himself upon dh and so it ends up a threesome (urghh).
Unfortunately this behaviour is quite obvious and as dh hardly ever says anything, ds has now taken it upon himself to "claim mum"! Ds hardly ever shares viewing nights ("too cool for us, has a life," etc) and as a rule is not prone to this kind of possessiveness, but it becomes quite clear that when it happens, it pisses dh off no end. Last night with dh and me, dh went off to make himself popcorn and none was offered to ds (usually shares with own dc or gets them some). V childish....
I realize how trivial all this sounds, but it is amazing how much resentment this engenders.
What's the best way to deal with this?
Ignoring just doesn't seem to be an option anymore. I gladly tell ds to stop "leaning" on me when he's becoming too heavy (bigger than me now), it just seems a bit unfair when the dsc act the same but don't get told off for coming on too strong (I'm really NOT referring to snuggling or other loving behaviour) or inappropriatly.
I tend to use humour to diffuse situations... Any thoughts?

Not sure how to handle this, so no helpful advice, but bumping for you as I can imagine how frustrating it is and hoping someone more useful will be along. DP's DDs are younger but there is definite territorial behaviour there, which is understandable when they are only with him 50/50 and the rest of the time he is with us, but it does grate when you're feeling nudged out in your own home!

My DCs will launch themselves on me for a cuddle, but I tend to keep one arm round DP or at least acknowledge the shift as I move from him to them, whereas he will let go and give his undivided attention to them, as they worm their way in between us on the sofa.

I have put a stop to it in bed though, asked him to keep his DCs on his side when they come in, not in the middle, as I don't need someone else's cheesey cold feet on me in the morning I don't even want my own DCs putting their clammy little feet on me!