We consider the dynamics of a barotropic fluid interacting with a bubble filled with uniform gas from the perspective of system interconnection in Lagrangian mechanics. Extending the existing geometric framework to an infinite-dimensional setting requires careful consideration of the appropriate duality pairing underlying the relationship between interaction forces and distribution constraints. We address both inviscid and viscous cases, including surface tension, and consider both free-slip and no-slip interface conditions. This work represents a first step toward building the geometric foundations for Rayleigh-Plesset equation and its related models.