His glorified body is capable of eating - remember He asked for a piece of fish? So who is to say it is incapable of feeling pain still?
Sure, He doesn’t go ‘ouch’ when we chew His body, but then we’re not offending or harming Him when we partake worthily, rather we’re obeying His command and receiving something that He most willingly gives to us. Desecration on the other hand - receiving unworthily, or abusing the Eucharist in other ways - well, I wouldn’t be so sure.
Think of it this way - a boxer doesn’t go ‘ouch’ when he’s punched in the ring according to the rules of the sport, even when the punch hurts, because in that circumstance he expects and volunteers to undergo a certain amount of physical discomfort.
But if that same boxer was bailed up outside his home by a thug and subjected to a beating, you bet he’d say ouch, because the blows are unexpected and involuntary.