Breastfeeding

Last night as I was sitting with my son, who is almost 12, I started wondering about how things would be different once our new baby arrives.  One question was...do I breastfeed openly in front of him, or use a coverup but stay in the same room?.?  I've always been open with him & not made nudity a big deal plus we are very close.  I just wonder if him being 12 is a little too old to just let it all hang out.  I definitely don't want him to think its a secretive thing, but I'm thinking having a coverup would be more appropriate since he'll be 12 when the baby arrives.  What are your thoughts?