Excession, by Iain M Banks.

Genar-Hofoen felt the Diplomatic Force officer's kiss through the few millimetres' thickness of the gelfield suit as a moderately sharp impact on his jaw followed by a powerful sucking that might have led someone less experienced in the diverse and robust manifestations of Affronter friendliness to conclude that the being was either trying to suck his teeth out through his cheek or had determined to test whether a Culture Gelfield Contact/Protection Suit, Mk 12, could be ripped off its wearer by a localised partial vacuum.  What the crushingly powerful four-limbed hug would have done to a human unprotected by a suit designed to withstand pressures comparable to those found at the bottom of an ocean probably did not bear thinking about, but then a human exposed without protection to the conditions required to support Affronter life would be dying in at least three excitingly different and painful ways anyway without having to worry about being crushed by a cage of leg-thick tentacles.

Gorgeous.