cheggers said:
As a matter of fact, I do sometimes refer to [my boss-wife] as Ma'am. She said she likes it.
Good... you found something that pleases your boss-wife. Keep up your good work addressing her in such ways.
Ma'am is, of course, an abbreviation for Madam, so addressing your boss-wife from time-to-time as "Madam [her first name]" might also please her. You might also try "Mistress" alternating occasionally with "Mistress [her first name]" to see if that pleases her as well. (It may be advantageous to address her respectfully in ways that don't become repetitious).
cheggers said:
I have done it [i.e., sucked her big toes], but she's not really into it. I understand the blow job comparison. One time I as bouncing my head up and down on her big toe just like a bj...
Maybe your boss-wife would have considered it more pleasing if you had gently sucked her big toe, not bouncing your head up and down but rather massaging it sensuously with your tongue as you sucked...
cheggers said:
...when she made me cum with her other foot.
That was very kind of your boss-wife...
cheggers said:
A couple times she held her toes to my mouth after I climaxed on them, but I failed her expectations and wasn't able to clean her properly.
Hm... it seem hard to know why your boss-wife may have been displeased without more detail. But, obviously she has good insight into your fetish for her feet. That's a plus.
You might consider asking (respectfully, of course) your boss-wife if, in the future when she feels you should be rewarded for good performance on your housework (or for other reasons), she would consider allowing you to take off your shoes, socks and pants (perhaps even all of your clothing) and then — while she relaxes, fully dressed in her easy chair, sipping her drink of choice (perhaps a glass of wine you have served her) — allow you to kneel before her and masturbate, finally holding out her cupped hand when you cum (so you cum in her hand), then feeding you your cum requiring you to lick up and swallow all of it.
Alternatively, at the end of this scene your boss-wife could require you to cum on her feet (her boots or pumps or bare feet, her choice), then lick up and swallow your cum from her feet. Then, after you've licked up and swallowed your cum, she could require you to continue kissing, licking and massaging her bare feet (after gently removing her boots or pumps) until she tells you to stop.
Either "reward strategy" would enable your boss-wife to reward you without any effort on her part, which she considers highly desirable (as you've said). Indeed, rewards of this nature, in addition to enabling you to orgasm, would be pleasurable for your boss-wife as well, because she could sit in her easy chair sipping (e.g.) her glass of wine, amusing herself watching you masturbate on your knees before her, while you do all the work of bringing yourself to orgasm.