Charlie is preparing for the wedding and sending out invitations but his lips keep swelling up and a visit to the doctor shows that it is not due to any allergic reaction. Finally he works out that it happens every time he talks about the up-coming wedding ceremony and is concerned that it is a sub-conscious sign that he does not want to go through with it. Fortunately he is reassured after a heart-to-heart with Caroline (thetvdb.com)