Alekhine defense Bishop sac?

so usually as black i play either the French, Caro-Kann, or rarely- the Sicilian, and to spice things up i have recently been trying Alekhine's defense (i refuse to play symetrically xD) anyway... the problem- not that i mind really, but nearly EVERYONE plays for an immediate bishop sac on f7. Is there an easy refutation nullifying the pressure? posted are a win and a loss (both with many mistakes, obviously) 

and a win just so i dont look too too bad ;)

I have played the alekhine a lot but never encountered these sacs. It's a pity, because i doubt white can come even close to equality after a random sac like that. It might not be very pleasant to handle black position in a quick time control game, but after all there is not an opening where the opponent can't blunder a piece for a couple of tricks if he wants. In the first line 5...Nb6 is definitely not a mistake, it's the mainline. 5...c6 is a playable alternative if you want to avoid that sac, but i would rather allow it. You played some bad/bizarre moves in that game but you were far from lost for most of the game, and this shows how "dangerous" this sacrifical idea is. Game two shows again that you have nothing to fear from this sort of stuff, even after playing the frankly bizarre 8...h6? which weakened the kingside and gave white some hope in a position where he was just a piece down.

Don't they try this too? 

This line is more common and less evil for white, but still black is at least equal (black central pawn majority and bishop pair in the long run are more important than the wandering king). Besides black is not forced to take on e4 at all and can mantain easy equality with many moves, including for example the interesting 2...b5!? leading to very original play. No prepared Alekhine player can fear the harmless 2.Bc4 (of course it's still a game of chess and you can either win or lose or draw, but you will  hardly lose because of the opening!)

The only anoying thing for us Alekhine players is when our opponent steadily refuses to advance the pawn like any sane person would do, but instead they move Nc3

well yes bresando i kind of expected/welcomed the apparent "bizareness" of some of my moves in the eyes of a higher rated player, most of which- other than my tactical incompetence, stemmed from the complete lack of a plan, if i kind of know how best to employ my strengths and the oppenents weaknesses in a position i normally do OK, but in a rapid game i dont have the experience or skill required to find all the subtleties of the weird positions that come out of these positions, getting left in a cramped position where they have easy development. would it be best to leave my king on the kingside where my pawns have been wrecked and my pieces have a difficult time migrating to the defense of the king? or should i instead aspire to walk the king over to the queenside as i attempted in the first game? (although unsuccessfully). @algorab i have not played the alekhine very many times yet, i've never even seen 2.Bc4.

 It's the Krejcik variation. By experience IMO It's a good for blitz line because the loss of 0-0 makes Black feel unconfortable but in return he can hit the exposed queen and pawnstorm the center.

are these bullet games?I play the Alekhine a lot....but never encountered these sacs in a long game.I'm sure they're not sound though

just blitz, but still... i've played it maybe 10 times against people close to my rating usually a little over, and maybe 8 times they've saced the bishop within a few moves if not immediately.

5...c6 is a good move. in the event of 6.Bc4 black can play Nc7 followed by Be6 and trading off that problematic c8 bishop for white's good one.otherwise there isn't a good square for this bishop in the dxe5 lines (since black fianchettos most of the times in these lines).although personally I prefer the classical 4...Bg4 to combat the modern