Choice for calls IMO are pass, 2♦, & 3♣. You are just strong enough to have a problem as partner could have reasonable values for 2♣. As we are V @ IMPs I would try 2♦ maybe that will give partner the info he needs to risk 3NT
no obvious problem with 3♠ since I think 3♦ was 100% forcing in your system. As far as the XX goes partner could have run just as easily as you could so I assume it is to play.
complete your planned action which was to show ♠ support over partner's forced call over 1NT. I would call 4♦ in case partner turns stupid on me and passes (I hate going down :) ) and bid 5♠ if instead he calls 5♦. You are forced to do it like this because of his 3NT call (probably instead of a sane 2NT call). A direct 4♠ would show a much weaker hand.
All the idgets play in the main bridge club. no sooner than i play 2 hands and they blow my cover, they say YOU IDGET. and I thought the correct spelling was idjit
Oh come on. You think 2NT was natural game forcing? Or it was an inv+ diamond raise and the OP forgot to tell us? The point is...that it was not specified ! and its' meaning should have been disclosed. If you think 3♦ is a clear nonforce then pass 2NT making it forcing has more advantages than picking the right part score