I love to kiss my beau after he goes down on me. After a particularly messy session, he laughed at me when I suckled on his beard - he knows I only did it because I really dig tasting myself (I suck on my toys after use, etc).
As for him, he'll kiss me after I go down on him, open mouthed and everything. But if he has ejaculated in my mouth, he tends to hold back until I've had some water or something. He's not into tasting himself at all.