No, waitaminnit, maybe I haven't... Is that the newer one; where Crazy CIA Dad et al get to met the other set of in-laws-to-be? Haven't seen that one yet -- but who cares; there were enough (and more than enough) "hilarious shenanigans" where the septic tank played a prominent part(*) in the first one.
Anyway, since it seems you missed my point (humble as it was), I'll spell it out forya:
Alex said he's gonna "stay away from" septic-tank systems.
OTOH, it is well-known here that Alex enjoys driving around America in his RV.
(For an example, wasn't that what he was driving when you met him and mrs Alex?)
The hygienic facilities in RVs are usually based on... You guessed it, a septic tank built into the vehicle.
But, do you really think Alex is going to give up his RV? Naaah! :-)
So he *can't* really be going to "stay away from" septic-tank systems.
So I was ribbing him a little, for saying stuff he can't live up to.
Which has approximately fuck-all to do with *any* film featuring Ben Stiller and Robert De Niro, AFAICS.
*Now* didyageddit?
(*): A bit *too* prominent a part for most people over the age of, say, twelve or so.