Concealing Hole Cards at Showdown

[DougI]

I'm a newbie at Holdem (about 6 mo.) and have played at a little bit at a local B&M and quite a bit online.
Recently, I struck up a home game with the neighbors.
Unfortunately, one of my neighbors did something I had never seen before and want to know if it is legal in Texas Holdem?
At showdown, when he called me, I'd show my hands, but then he would only show part of his hand (enough to beat mine).
When I asked to see the other card, he refused. He said he only needed to show enough of his hand to beat mine.
Is that true? Can you conceal part of your hole card under any circumstances when it gets to the river and all bets are done?
It's definitely not like that online and I don't believe it's like that at a B&M place.
Needless to say, I wasn't able to get a feel for the type of pre-flop hands he was playing almost all night long.

Thanks In Advance.

[ScottTheFish]

You absolutely have the right to see both his cards if he goes to showdown. He's being a prick, IMO.

[astroglide]

the dealer sucks if they let that get by. both cards absolutely have to be shown.

[DougI]

The problem was that I was probably the second most knowledgable player at the table (that's not saying much either). The guy who kept doing this to me had played holdem much longer (but mostly from home games where he lived previosly) and therefore I wasn't in the position of authority to say that you have to show me the other card.
Now I need to find some official poker book so that I can prove him wrong or he will argue that there is no reason to show the other card if he has me beat with the pair he made from the board and his one hole card.

Thanks guys for your experience on the matter.

[astroglide]

http://www.tiltless.com/LuckyChances...ookProject.htm

72 All cards of a called hand must be shown face-up on the table in order to win any part of a pot in a showdown. Players must expose their cards in order to play the board.

[cardcounter0]

or to translate it in Texan, "It takes two cards to win"

[Cosimo]

In fact, you have the right to see his cards even if you aren't involved in the hand or if he mucks both after calling.

[smokingrobot]

i hate that crap.
i play a game with some friends who are learning how to play, and they started doing that [censored] because one of the other people in the game did that. i was constantly asking to see both cards, glad i have some evidence to back this up.

[Billman]

Actually it happens to depend on who you're playing against. If you play against Dick Cheney, you only need to tell the other player what you have.