Always look a Trojan Horse in the mouth

Always look a Trojan Horse in the mouth

Inspired by a tweet by SecurityHumor in which he adapted the old idiom about never looking a gift horse in the mouth by replacing "gift" with "trojan". Obviously, though, trojan horses aren't good gifts so you probably want to do the opposite in that case.

[2017-07-15: edited to add this because the Internet loves images]

from here