Nobody should be offering to treat somebody to dinner if they're going to go and begrudge them for choosing what they want.

Your tip is nice n all, I can see your trying to be considerate. But you must recognise that for the person spending its an asshole thing to be upset that somebody has accepted your generosity? Therefore as the receiver you should gratefully accept the offer and not feel guilty about it.

If there are conditions on a gift I'd rather no receive it or at least be informed of those conditions up front (like if a mate says they ll cover me for a 50 quid meal but don't take the piss any more than that, tjays cool), what I don't want is hidden conditions and invisible rules on whether or not I'm not an asshole because I've ordered to much. That is not a nice gift to receive, at all.