DS' (4) behaviour changes when both parents are around - attention seeking?

[Arana]

DS is a lovely, thoughtful, kind boy, but quite challenging. He has a few behavioural problems, very few social skills, and can get very anxious about things.

One thing we've really noticed, is that when me and DH are both there, his behaviour gets much, much worse.

I don't think that the family dynamics changes much when both of us are present, and it doesn't matter who the original parent is and who joins. It can be a passive situation (watching TV together) or an active situation (playing football in the park) but either way his behaviour gets worse. If we're at home he'll start rolling around on the floor, making silly noises, general attention seeking behaviour. It has become so bad that we try to parent him separately, as it's just easier. The more people there are (for example, if grandparents or adult friends) again, the worse his behaviour gets.

Any tips on how to deal with this?

People we know, and family members have mentioned (usually in hushed tones) things like ADHD and aspergers. We don't want to medicalise him, but it would seem that a lot of his behaviour fits those patterns. Should we just leave it until it becomes a problem at school, or can we work on it to minimise the problems?

This is very similaer to our son who is now 5, this behaviou began around two and he has got a lot better over the last year.
We contacted our HV and her advice was generally ignoring and trying to carry on conversation with other person, when you have finishes say something like ' now i have finished talking to Dad it is you turn to speak' . Something else suggested was putting up you rhand whnw you wanted to speak but this didn't really work.
If yu are at home ignore tantrums etc and they are not getting attention try to walk away
OUr Ds also yelled at top of his voice when you got a phone call cos he wasn;t getting attn