I haven’t been following this thread since the first page, however it looks like Budget Player’s mother may be asking for advice on another site.
http://www.slate.com/articles/life/dear_prudence/2012/03/my_18_year_old_son_is_dating_a_woman_30_years_his_senior_.html
Prudence’s answer:
A: She may not be his teacher, but she’ll be his teacher, all right. This does not feel very OK, and if the sexes were reversed it still wouldn’t. A 30-year age difference for a first romance is definitely designed to make one’s parents unhappy. As “nice” as this woman may be, she sounds utterly oblivious to the inappropriateness of her behavior. Your son should be focused on his homework and going to college—if that’s on his agenda—so as with any romance you need to make sure he’s not devoting all his time to his new girl, ah, lady friend. However, he’s 18, and the bigger deal you make of this, the deeper his love is likely to be. You can express your understandable concern that he’s dating someone older than you, then back off and make sure he’s studying for his biology test.
Okay, to sum it up: Budget Player! Focus on your biology lessons! We must ignore you now, and not express any concerns .. lest your love grow deeper.
BTW. . .the OP is not dating an “older woman” as the thread title suggests, he’s dating her mom.
Yeah, so? I dropped into this thread to see why it is still alive.
Dude is getting it on with his own Mrs Robinson, except not nearly as hot as Anne Bancroft. The correct reaction is to say, “You go, kid,” while quietly dry-heaving in the background. It’s what a gentleman does.
I was in the OP’s shoes, many decades ago. Remember hearing about it? No? 
I bet Benjamin didn’t have to beg Mrs. Robinson to let him go down on her while she shyly clutched the sheet up over her face. (Unless that was in the DVD extras.)
And the fact that Hoffman (30, born 1937) was only 6 years younger than Bancroft (36, born 1931) when The Graduate was filmed in 1967.
Here’s the thing, and it’s probably been articulated already:
Right now it’s pretty cool, but you’re not going to want to have a relationship with 70 year old when you’re 40, or even a 60 year old when you’re 30 (that’s only 12 years away). Think about those numbers and how attractive she’ll be at those ages. If you’re in it for more than biological purposes, do you really want to be in a relationship where your wife is going to die 30 years before you? You either have to live a long time without a mate, or start over around age 40-50…not a very easy thing to do.
But, ultimately, if it’s what both of you want, who gives a fuck. Does it really matter what the hell other people think?