Quote 1
GRATIANO
My Lord Bassanio, and my gentle lady,
I wish you all the joy that you can wish,
For I am sure you can wish none from me.
And, when your honours mean to solemnize
The bargain of your faith, I do beseech you
Even at that time I may be married too. (3.2.193-198)
Graziano's marriage to Nerissa is a calculating, unornamented version of the institution that is actually a neat parallel to Bassanio and Portia's hookup. Graziano says as much when he declares that he and Bassanio are the "Jasons" who have "won the fleece" (3.2.6).
Quote 2
GRAZIANO
But who comes here? Lorenzo and his infidel (3.2.5)
When the newly married Jessica and Lorenzo show up at Portia's pad in Belmont, Graziano refers to Jessica as an "infidel," insisting that she is different from the Christians... even though she has recently converted.
Quote 3
GRAZIANO
Nerissa [indicating Jessica]. Cheer yon stranger. Bid her welcome (3.2.6)
When Graziano tells Nerissa to "welcome" Jessica to Belmont, we get a sense of Jessica's physical isolation onstage. The word "yon" indicates that she's standing apart from the other characters, and the fact that she needs "cheer[ing]" implies that she's sad or uncomfortable. This suggests that Jessica may not be (or feel) very welcome in Belmont, despite her recent conversion to Christianity.